As a heat treatment device including a heat treatment chamber which accommodates an object to be treated, a cooling gas supply unit which supplies a cooling gas into the heat treatment chamber, and a cooling gas circulation unit which circulates the cooling gas in the heat treatment chamber, for example, a multi-chamber type multi-cooling vacuum furnace disclosed in the following Patent Document 1 is known. The multi-chamber type multi-cooling vacuum furnace includes a liquid nozzle and a gas nozzle disposed in a cooling chamber so as to surround the object to be treated and configured to supply a cooling liquid and a cooling gas.